A student determines the molar mass of an unknown volatile liquid by vaporizing a sample in a container of fixed volume at a constant temperature and pressure. Under these conditions, the density of the unknown vapor is measured to be \(3.60 \text{ g/L}\). Under the exact same temperature and pressure, the density of pure \(\text{O}_2\text{(g)}\) (molar mass \(32.0 \text{ g/mol}\)) is \(1.20 \text{ g/L}\). Based on these data, what is the molar mass of the unknown liquid?